docs: def load_keys():
      """Loads Twitter keys.
  
      Returns:
          tuple: consumer_key, consumer_secret, access_token, access_token_secret
      """
      consumer_key = os.environ.get('CONSUMER_KEY')
      consumer_secret = os.environ.get('CONSUMER_SECRET')
      access_token = os.environ.get('ACCESS_TOKEN')
      access_token_secret = os.environ.get('ACCESS_TOKEN_SECRET')
  
      return consumer_key, consumer_secret, access_token, access_token_secret